Unusual Colors in Cycles from Lighting / Rendering

Hello Blender Artists!

I’ve been attempting to work through Blender Guru’s ‘Mastering Lighting in Blender’ to start practicing using Cycles and lighting but it seems that whenever I even attempt to add the ‘main light’ to the scene I get these insane colors that don’t match up at all with what he’s demonstrating. I downloaded the file available at the website and simply added a plane, set it to emit, and voila, I get the following (a selection of a render, didn’t feel like letting it render all the way out):

Just curious if I’m missing some settings for using Cycles as this is the first project I’ve approached using it.

Thank you very much!

The magenta colour indicates you have missing textures.
Cycles cannot use textures that are packed in the blend file like the ones supplied in the blend file you’ve downloaded. You will first need to unpack them from the File / External Data menu

Fantastic, thank you very much Richard! Apologies if this was a simple answer, I tried all kinds of google combinations (“purple crazy colors cycles blender” etc…) and couldn’t get anything to turn up.